Field of the Invention
The present invention relates to an image pickup apparatus, a method of controlling the same, and a storage medium, and more particularly to a method of setting a shutter speed for still image shooting and moving image recording.
Description of the Related Art
Conventionally, in an image pickup apparatus, such as a digital camera, a shutter speed can be set and changed in increments associated with exposure stops (exposure steps) e.g. within a range of 1/8000 to 30 seconds.
For example, in setting a shutter speed, as a method of facilitating shutter speed setting by associating a frame rate of a moving image with the shutter speed, there has been proposed a method of determining a frame rate based on a shutter speed set for still image shooting (see Japanese Patent Laid-Open Publication No. 2008-301286).
Incidentally, the shutter speed for moving image shooting (pickup) cannot be set to be longer than the reciprocal of the frame rate (time required to pick up one frame of a moving image). That is, a lower limit value (long exposure-side limit value) of the shutter speed in moving image shooting is the reciprocal of the frame rate.
However, in a case where exposure step increments are ½-stop increments or 1-stop increments, there is a case where a value close to the reciprocal of the frame rate cannot be found in values which can be set as exposure values. For example, when the frame rate is 25 fps, the lower limit value (long exposure-side limit value) of the shutter speed for moving image shooting is 1/25 seconds. However, when the exposure step increments are ½-stop increments, there is no setting value of 1/25 seconds, and a settable value which is shorter than the 1/25 seconds and is closest to 1/25 seconds is 1/30 seconds.
Therefore, even when a user desires to set the shutter speed to as slow a value as possible, the shutter speed cannot be set up to the lower limit (long exposure-side limit value) of the shutter speed for moving image shooting. That is, a shutter speed which is slightly shorter than the lower limit value is a limit to which the shutter speed can be set.